Closure for trunk compartments



- July 14, 1959 wu 2,894,276

CLOSURE FOR TRUNK COMPARTMENTS Filed March 51, 1955 2 Sheets-Sheet l INVENTOR 1 v BERNHA RD wuu-r I ATTORNEYS y 1959 B. WULFF 2,894,276

CLOSURE FOR TRUNK COMPARTMENTS Filed March 51, 1955 2 Sheets-Sheet 2 INVENTOR 22 1 BERNHARD WULFF ATTORNEYS.

United States ll CLOSURE FOR TRUNK COMPARTlVIENTS Bernhard Wullf, Sindelfingen Kries Boblingen, Germany, assignor to Daimler-Benz Alrtiengesellschaft, Stuttgart- Unterturkheim, Germany The present invention relates to simple mechanism for easy opening hinged container lids, particularly those of trunk compartments of automobiles, with the aid of a beam-spring.

Prior arrangements of this kind were usually inflicted with various disadvantages. Lids, especially of trunk compartments provided with supporting braces, usually require that, when opening the same, the weight of the lid, as well as the frictional resistance of the braces, which also easily stick or bind, must be overcome, while the lid will remain in the open position only by the provision of suitable stops or retaining means. Then again, it is difiicult when attempting to close the lid, to release these retaining means and at the same time hold back or restrain the lid from slamming down. Although there have been lid constructions in which the weight of the lid was balanced to a considerable extent, they had the disadvantage that the lid would not properly close as desired.

It is the principal object of the present invention to provide a lid, especially for trunk compartments of automobiles, which overcomes the above-mentioned disadvantages of prior structures by the provision of very simple and elfective means which may be produced very easily at low cost.

Another object of the present invention is to provide a mechanism which increases the gravitational force at certain positions of the lid and by suitable counter pressure counteracts the same almost entirely at other points during the pivotal movement of the lid. For opening the lid and retaining it in open position, it is not necessary to operate and engage a stop or locking mechanism, and the closing operation is absolutely reliable and not interfered with by any additional structural elements. Also the interior of the container or trunk compartment is not obstructed by such additional elements to any appreciable extent, and such elements are designed so as to allow free access to the interior of the compartment from all three sides.

A feature of the preesnt invention resides in the provision of a beamspring which extends substantially parallel to the axis of the hinges which connect the lid with the compartment proper, and which is rotatably mounted substantially at the center of the compartment wall which is suitably reinforced for this purpose. This beam-spring is provided to have an adequate initial tension when the lid is in the closed position, and its two ends are likewise pivotally connected with the hinges and are also moveable in a longitudinal direction relative thereto. The hinges themselves each consist of a hinge bracket which is secured to the inside of the compartment wall and includes the hinge bearing, and a curved hinge arm which is pivotable about the hinge axis and secured at its other end to the lid, and is provided at one portion thereof with a hearing hole for receiving one end of the beam-spring.

The torsional moments which, according to the invention, either amplify the gravitational force or partly neutralize or even exceed the same, depending upon how easily the lid is to be opened and closed, are obtained atent O" ice by a suitable selection of the distances of the plane of the central pivotal hearing from the respective planes of the center of the bearing holes in the hinge arms, and from the plane of the hinge axis.

The beam-spring according to the invention forms, for example, a bow-shaped steel rod which,'when released, is curved toward one side and the two ends of which are slightly bent back so as to form short straight portions which are to be inserted and guided in the bearing holes of the hinge arms.

Further objects, features, and advantages of the present invention will be apparent from the following detailed description thereof to be read with reference to the accompanying drawings, in which- Figure 1 is a side view of the closure mechanism applied to a trunk compartment lid of an automobile according to the present invention with the compartment lid in a closed position,

Figure 2 is a perspective view of the closure mechanism with the trunk compartment lid in an open position,

Figure 3 shows schematically the hinge opening function in cross section through the lid and compartment wall, and

Figure 4 shows a side view of a modification of the closure mechanism according to the present invention.

Referring to the drawings, the lid 1 of the trunk compartment is secured to the compartment wall 4 by means of hinges 2 and 3 and is pivotable about the hinge pins 5. Figure 1 illustrates the lid 1 with the hinges thereon in the closed position shown in full lines and in the open position shown in dotted lines while Figure 2 illustrates the lid 1 in the open position. The rigid parts of the hinges which have to bear and transmit considerable stresses taken up from the lid 1, therefore have to be Well secured to the compartment wall, for example, by spot welding. The beam-spring 7 is pivotally mounted at its center on the compartment Wall 4 by means of a bearing bracket 8, and secured from shifting in a longitudinal direction by adjustable stops 9 and 10. Bracket 8 is preferably secured to the compartment wall 4 by means of a reinforcing plate 11. The two ends 12 and 13 of the beam-spring 7 are pivotally mounted in the hinge arms 14 and 15 and are longitudinally slideable therein, preferably by means of suitable bushings 16 and 17, respectively.

The beam-spring 7 is mounted on the hinge arms 14 and 15 and the central bracket 8 under a certain initial tension, the curvature of the spring thus being flatter under such tension than when it is completely released. Its radius is dependent upon the requirement that the torsional moment transmitted from the spring. 7 to the hinge arms 14 and 15 will produce the required force at each position of the lid so as to move the same.

For a better illustration of the relative arrangement of the various elements as applied to a trunk compartment of an automobile, the same have been shown in Fig. 2 in a perspective view.

In Fig. 3, the opening operation has also been illustrated diagrammatically. The hinge and the beam-spring have been shown therein both in the locked position as well as in the open position of the lid. This drawing also indicates the movement of the spring ends and their position at certain points in the opening or closing movement of the lid. The hinge arm 15 is mounted on the wall of the trunk compartment 4 so as to be pivotable about the hinge axis 5, while the center 8 of the beam-spring made in the form of a bow-shaped steel rod is pivotally mounted on the wall of the trunk compartment, but within a plane different from that passing through the center of the hinge pin 5 and bearing bracket 8. In the closed position of the lid, the spring ends will be located at the point 13. At any movement of the lid 1, these spring ends describe quently their respective distance from their stationary center 8 and thus also the tension of the spring varies accordingly. V V

, he distance between the spring ends 12 and 13 and the location ofthe bearing 8 determines the tension of the When opening the lid, the moments of the spring force and the gravitational force preferably have to be overcome onlyfor a short distance during the openin'g movement, and the cooperation of these two forces will assure a proper closing of the lid at any time and even under adverse conditions.

Further raising the lid increases the spring tension to its maximum value which is reached when the points '5, i8, and l3'ylie within the same plane which, as indicated in Fig. 3 in dotted lines, forms a straight line connecting "the center of "the hinge axis with the center of the central spring bearing, and the center of the bearing holes in the hinge arms. At the point 1 3, the beam-spring will have its least curvature, and thus its greatest force. The positionof the spring ends on a line connecting the two bear ing points, i.e. the bearing of the hinge arm and that of the center of the spring, causes the spring force to act in the direction toward the center of the bearing of the hinge arm, and the leverage which produces an opposed torsional moment against the action of the moment produced in a certain position by the force of gravity becomes zero. By further raising the lid 1, the spring end 13 moves to the position 13". The spring tension, during "this movement from 13' to 13 decreases to below the te'nsion at 13. During the same opening movement of the lid 1, however, the effective lever arm increases appreciably 'so that in the fully open position of lid l, the spring is capable of securely holding the lid in this position.

v According to another embodiment of the invention as illustrated in Fig. 4, the spring force is made effective during the opening and closing movements especially in V the upper and lower lid positions by permitting the effective point of the spring action on the hinge arm to be shifted to different positions. This is preferably carried out by means of a curved slot 20 eccentrically disposed to 'the center '5 of the hinge arms 15 in each of the rigid hinge parts 22. The springs ends 12, 13 engage these slots 20 and are guided therein during the opening and closing movement of the lid 1. During the opening movement thereof, the distance between the spring ends 1 2, 13 from the pin center's increases progressively. In order to make this movement of the spring ends 12, 13 "possible, a gatelike and approximately radially extending slot 24 i's provided in each of the hinge arms 15' in which the spring-ends 12, 13 are also guided and are movable in a direction per endicular to the longitudinal axis of the spring ends. The combined movements of the spring ends with respect to the hinge center results in an inki'reased leverage of the spring force on the hinge and the lid as it is opened.

2,994,27 p r r The relative dimensions of the various parts and their distances from each other obviously depend upon the weights and forces prevailing in each particular case, and they should be chosen so that the lid may be easily opened and safely retained in the open position, and also be reliably closed without any muscular effort.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof I wish to have it understood that it is in no way limited to the details of such embodiments or to the Specific examples described, but is capable of numerous modifications within the scope of the appended claim.

Having thus fully disclosed my invention what I claim A spring-loaded hinge construction for opening and closing the lid of a trunk compartment of an automobile having an inner compartment wall, comprising a pair of hinge arms, bracket means secured to said compartment wall,"pivot means for pivotally mounting one 'end of each of said hinge arms thereto, means for rigidly securing the other end of each of said hinge arms to said lid, a bow-shaped beam spring of substantial curvature having two free ends and being disposed between said hinge arms, means for rotatably mounting said be'ar'n spring on said compartment Wall intermediate said two hinge arms, each of said hinge arms and each of said bracket means being provided with a slot for 'sirnulta'ne ous engagement with each of said spring ends'to enable relative slidable movement of said ends in the direction parallel to the axis of said slots, said slots in said hinge arms extending in a direction substantially parallel and slightly to one side of a plane including the axes of said pivot means, and the axis of said mounting means when said lid is in the closed position thereby tending to retain said lid in the closed position, each of said "slots in said bracket means being curved and extending from. said one side of said plane to the other side of'said plane, said simultaneous engagement of said spring ends with said slots effecting an increasing lever arm of the ends of "said spring with respect to the center of said pivot means to compensate for the decreasing tension of said beam spring and to substantially counteract the weight of said lid in all positions thereof during the opening movement of said lid.

References Cited in the file of this patent UNITED STATES PATENTS 1,292,725 Dexter Jan."28, 19'1'9 2,l05,-07l Bowers J an. 11-, 1938 2,279,992 Jackson et al Apr. 14,1942 2,320,752 Roethel June 1, 1943 2,650,846 Allen Sept. 1, 1953 2,654,118 Scott Oct. 6, 1953 2,688,764 Squire Sept. 14,1954

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